<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <link rel="stylesheet" type="text/css" href="./index.css" />
  <title>demo</title>
</head>
<body>
  <div class="container">
    <div class="dot dot-1"></div>
    <div class="dot dot-2"></div>
    <div class="dot dot-3"></div>
  </div>
  <svg xmlns="http://www.w3.org/2000/svg" version="1.1">
    <defs>
      <filter id="goo">
        <feGaussianBlur in="SourceGraphic" stdDeviation="10" result="blur" />
        <feColorMatrix in="blur" mode="matrix" values="1 0 0 0 0  0 1 0 0 0  0 0 1 0 0  0 0 0 21 -7"/>
      </filter>
    </defs>
  </svg>
</body>
</html>